1. Field of the Invention
This invention relates generally to assemblies which wrap around circular pipes and similar devices which require that the abutting ends be pinned together such that the pins will be in shear and will be benefited by multiple shear planes to carry the shear loads.
2. Description of the Related Art
Pipe support assemblies frequently referred to as slip assemblies are frequently hinged so that they can be engaged around pipe while it is supported from the top. The slips are segmented units which have sharp teeth in the inner surface to grab the pipe with a high friction coefficient and are characteristically tapered on the back (8xc2x0 to 15xc2x0 with respect to the centerline) so that they will be wedged against the pipeline. The slip segments fit within a bowl which has a corresponding inner taper. The bowls will be segmented in 2 to 4 pieces to allow the hinging around the pipe. The interface between the sections will normally remained pinned to allow flexibility, except for one interface. That interface will have alternating finger like projections from the edges of each of the slip bowl sections that mesh together when they are brought to adjacent positions.
On the edge of a bowl section, each of the fingerlike projections will have a hole, with the holes being on a common centerline. When the edges of two bowl sections are brought together and the fingerlike projections mesh, the holes on one edge will be aligned with the holes on the other section and allow a pin to be inserted into the aligned holes.
When the slip segments are loaded with a pipe section and cause an outward force due to the taper on the slip segments and bowl, the outward force is translated into a circumferential or hoop force in the bowl, causing a shear stress in the pin. The force is divided by the number of times the pin is put in shear in the construction.
In conditions involving larger pipe sizes and high loads, the diameter and length of the pin can cause the pin to be long and heavy. Large and long pin sizes promote the need for automation of operation of the insertion and removal of the pin. The need for remote operation of the pin such as in the mast of a rig or on the seafloor also promote the need for remote operation. The longer the pin, the longer the operating cylinder. Long cylinders complicate the design and add to system space considerations.
The present invention is directed to overcoming, or at least reducing the effects of one or more of the problems set forth above.
The object of this invention is to provide a pin connection which can be remotely operated.
A second object of this invention is to provide for remote or power operation of the pin, with a reduced space requirement.
A third object of this invention is to provide means for accurately aligning the ends of the pipelines for welding and laying.
Another object of this invention is to provide a pin connection which is failsafe to the closed or locked position.